Plasmon properties of metal tips can be used for ablation, ionization, and mass spectrometry imaging with nanoscale resolution.

Background: The novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has spread worldwide.Hypothesis: The possible risk factors that lead to death in critical inpatients with coronavirus disease 2019 (COVID‐19) are not yet fully understood.Methods: In this single‐center, retrospective study, we enrolled 113 critical patients with COVID‐19 from Renmin Hospital of Wuhan University between February 1, 2020 and March 15, 2020. Patients who survived or died were compared.Results: A total of 113 critical patients with COVID‐19 were recruited; 50 (44.3%) died, and 63 (55.7%) recovered. The proportion of patients with ventricular arrhythmia was higher in the death group than in the recovery group (P = .021) and was higher among patients with myocardial damage than patients without myocardial damage (P = .013). Multivariate analysis confirmed independent predictors of mortality from COVID‐19: age > 70 years (HR 1.84, 95% CI 1.03‐3.28), initial neutrophil count over 6.5 × 10⁹/L (HR 3.43, 95% CI 1.84‐6.40), C‐reactive protein greater than 100 mg/L (HR 1.93, 95% CI 1.04‐3.59), and lactate dehydrogenase over 300 U/L (HR 2.90, 95% CI 1.26‐6.67). Immunoglobulin treatment (HR 0.39, 95% CI 0.21‐0.73) can reduce the risk of death. Sinus tachycardia (HR 2.94, 95% CI 1.16‐7.46) and ventricular arrhythmia (HR 2.79, 95% CI 1.11‐7.04) were independent ECG risk factors for mortality from COVID‐19.Conclusions: Old age (>70 years), neutrophilia, C‐reactive protein greater than 100 mg/L and lactate dehydrogenase over 300 U/L are high‐risk factors for mortality in critical patients with COVID‐19. Sinus tachycardia and ventricular arrhythmia are independent ECG risk factors for mortality from COVID‐19.

It is well established that certain carboxylic acid compounds can effectively inhibit tyrosinase activity. This study investigated the mechanisms by which four carboxylic acid compounds—3-phenyllactic acid, lactic acid, L-pyroglutamic acid, and malic acid—inhibit tyrosinase and melanogenesis. IC₅₀ values for mushroom tyrosinase inhibition ranged from 3.38 to 5.42 mM, with 3-phenyllactic acid (3.50 mM), lactic acid (5.42 mM), and malic acid (3.91 mM) exhibiting mixed-type inhibition, while L-pyroglutamic acid (3.38 mM) showed competitive inhibition, as determined by enzymatic kinetic analysis. Additionally, the acidification effects of lactic acid, L-pyroglutamic acid, and malic acid contributed to the reduction in tyrosinase activity. Furthermore, all four carboxylic acid compounds effectively inhibited DOPA auto-oxidation (IC₅₀ = 0.38–0.66 mM), ranking in potency as follows: malic acid (0.38 mM) > lactic acid (0.57 mM) > 3-phenyllactic acid (0.63 mM) > L-pyroglutamic acid (0.66 mM). These compounds also demonstrated a dose-dependent reduction in melanin production in B16-F10 cells. Proteomic analysis further revealed that these compounds not only inhibit key proteins involved in melanin synthesis, such as tyrosinase, tyrosinase-related protein 1, and tyrosinase-related protein 2, but also potentially modulate other genes associated with melanogenesis and metabolism, including Pmel, Slc45a2, Ctns, Oca2, and Bace2. Network toxicology analysis indicated that these four compounds exhibit a low risk of inducing dermatitis. These findings suggest that these compounds may indirectly regulate melanin-related pathways through multiple mechanisms, highlighting their potential for further applications in cosmetics and pharmaceuticals.

The fruit of Rosa laevigata Michx. (FR), a traditional Chinese herb utilized for the treatment of a variety diseases, has notably diverse pharmacological activities including hepatoprotective, anti-oxidant, and anti-inflammatory effects. Despite ongoing research on illustrating the underlying anti-inflammatory mechanism of FR, the principal mechanism remained inadequately understood. In this study, we investigated in depth the molecular mechanism of the anti-inflammatory actions of the ethanol extract of FR (EFR) and its potential targets using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. We showed that EFR effectively ameliorated the overproduction of inflammatory mediators and cytokines, as well as the expression of related genes. It was further demonstrated that LPS-induced activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) were significantly inhibited by pretreatment with EFR, accompanied by a concomitant decrease in the nuclear translocation of the p65 subunit of NF-κB and activator protein 1 (AP-1). In addition, EFR pretreatment potently prevented LPS-induced decreased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK). Our data also revealed that the activation of AMPK and subsequent inhibition of the mammalian target of the rapamycin (mTOR) signaling pathway was probably responsible for the inhibitory effect of EFR on LPS-induced inflammatory responses, evidenced by reverse changes observed under the condition of AMPK inactivation following co-treatment with the AMPK-specific inhibitor Compound C. Finally, the main components with an anti-inflammatory effect in EFR were identified as madecassic acid, ellagic acid, quinic acid, and procyanidin C1 by LC–MS and testified based on the inhibition of NO production and inflammatory mediator expression. Taken together, our results indicated that EFR was able to ameliorate inflammatory responses via the suppression of MAPKs/NF-κB signaling pathways following AMPK activation, suggesting the therapeutic potential of EFR for inflammatory diseases.

Fresh Spirulina is more favorable than dried one, yet its ease of deterioration necessitates production of biomass that can be immediately consumed. We developed a prototype household photobioreactor and studied the semi-continuous cultivation and harvest conditions within 107 days. Three growth phases were observed featuring different growth rate and recovering time after harvest. Nutrients were consumed at rates of Fe > N > P > Mg > K. The pH mounted rapidly when below 9 and varied slowly between 9 and 10, whose variation positively correlated with that of biomass concentration. Bacterial load was at a constant level of about 2 × 10⁴ CFU, indicating good sanitary condition. Harvesting efficiency improved with greater biomass and filtration sack mesh number until reaching 3.5 g·L⁻¹ and 200, respectively. We hope this study can help the method development of fresh Spirulina cultivation in miniaturized systems.